E

C

/R Incorporated Providing Environmental Technical Support Since 1989

6330 Quadrangle Drive, Suite 325  Chapel Hill, North Carolina 27517

Telephone: (919)484-0222  Fax: (919) 484-0122

MEMORANDUM

DATE: July 28, 2011

SUBJECT: Oil and Natural Gas Production MACT and Natural Gas Transmission and 

Storage MACT – Technology Review

FROM: Bradley Nelson, EC/R Incorporated

TO: Bruce Moore, EPA/OAQPS/SPPD/CCG

The purpose of this memorandum is to present the results of an investigation to identify 

any developments in practices, processes, and control technologies for hazardous air pollutants

(HAP) emission sources for the Oil and Natural Gas Production Maximum Achievable Control 

Technology (MACT) and the Natural Gas Transmission and Storage MACT regulations. This 

analysis is part of EPA’s review efforts in accordance with section 112(d)(6) of the Clean Air 

Act.

Section 1 provides background information on section 112(d)(6), the source categories, 

and the requirements of the National Emission Standards for HAP (NESHAP) that address 

emissions from these categories. Section 2 discusses the exploration of developments in 

practices, processes, and control technologies that have occurred since the original development 

of these NESHAP, and section 3 provides the conclusions of this investigation.

1.0 BACKGROUND

Section 112 of the Clean Air Act (CAA) requires EPA to establish technology-based 

standards for listed source categories. These technology-based standards are often referred to as 

MACT standards. The Oil and Natural Gas Production MACT (40 CFR 63, subpart HH) applies 

to major and area sources and regulates HAP emissions from oil and natural gas production 

facilities. The Natural Gas Transmission and Storage MACT (40 CFR 63, subpart HHH) 

requirements apply to major sources and regulates HAP emissions from natural gas transmission 

and storage facilities. Extracted streams and recovered products, processes and operations, and 

HAP emission points are described in the following sections. Section 112 contains provisions 

requiring EPA to revisit these standards. Specifically, paragraph 112(d)(6) section states:

(6) REVIEW AND REVISION. – The Administrator shall review, 

and revise as necessary (taking into account developments in practices, 

processes, and control technologies), emission standards promulgated 

under this section no less often than every 8 years.
2

To comply with this CAA requirement, EPA conducted a technology review for each of 

these MACT standards for major sources. 

1.1 Oil and Natural Gas Production MACT

The oil and natural gas production source category includes the separation, upgrading, 

storage, and transfer of extracted streams (primarily hydrocarbons) that are recovered from 

production wells. The extracted streams and recovered products for this source category include 

crude oil, condensate, natural gas, and produced water. The oil and natural gas production 

source category includes the processing and upgrading of crude oil prior to the point of custody 

transfer, and natural gas prior to entering the pipeline systems associated with the natural gas 

transmission and storage source category. The types of processes and operations in this source 

category include production wells, dehydration units, tank batteries, natural gas processing 

plants, and offshore production platforms. The HAP emission points regulated by the existing 

MACT standards are dehydration units, storage vessels with the potential for flash emissions, 

and equipment leaks.

Dehydration Units

Dehydration units are used as stand-alone units that remove water and other condensates 

in natural gas from an individual well or several wells. In addition, dehydration units may be 

part of various processing units at condensate tank batteries, natural gas processing plants

andoffshore production platforms. Dehydration is necessary to remove water vapor which may 

form hydrates that can cause corrosion and plug equipment lines. Triethylene glycol (TEG) 

dehydration units account for most of the population of dehydration units, with ethylene glycol 

(EG), diethylene glycol (DEG), and solid desiccant dehydration units accounting for the 

remaining portion. The subpart HH control requirements are applicable to dehydration units that 

process an actual annual average flow rate of greater than or equal to 3 million standard cubic 

feet per day (MMscf/d) and emit benzene emissions greater than or equal to 1 ton per year (tpy).

The current NESHAP requires that a closed vent system be used to capture HAP 

emissions from the glycol dehydrator process vent and flash tank (if a flash tank is present), and 

to route those HAP emissions to a control device or series of control devices that reduce the HAP 

mass emissions by 95 percent, or reduce the benzene emissions to less than 1 tpy.

Storage Vessels with the Potential for Flash Emissions

Storage vessels with the potential for flash emissions refer to the collection of storage 

vessels that contain a hydrocarbon liquid with a stock tank gas-to-oil ratio (GOR) greater than or 

equal to 1,750 cubic feet per barrel (ft3/bbl), and an API gravity of greater than or equal to 40 

degrees, and an actual average hydrocarbon liquid throughput of greater than or equal to 500 

bbl/day. Flash emissions occur from these vessels when dissolved hydrocarbons evolve (or 

flash) from the tank contents when the fluid pressure is reduced. These storage vessels typically 

store crude oil, condensate, or other hydrocarbon liquids at production facilities prior to transfer 

of the oil or natural gas to a refinery or natural gas processing plant. Condensate, also referred to 

as retrograde gas, consists of hydrocarbons that are in a gaseous state under reservoir conditions, 

but become liquid in either the wellbore or the production process.
3

The current NESHAP requires that emissions of HAP from storage vessels with the 

potential for flash emissions be controlled using a cover that is connected to a closed vent 

system. The captured HAP emissions are then required to be routed to a control device or series 

of control devices that reduce the HAP mass emissions by 95 percent.

Equipment Leaks

Equipment leaks are emissions from valves, pump seals, flanges, compressor seals, 

pressure relief valves, open-ended lines, and other process and operation components. The 

amount of HAP emissions from equipment leaks is dependent on the type and number of 

equipment components and the concentration of HAP components in the component stream.

Components such as pumps, valves, pressure relief valves, flanges, agitators, and compressors 

are potential sources that can leak due to seal failure. Other sources, such as open-ended lines, 

and sampling connections may leak for reasons other than faulty seals. In addition, corrosion of 

welded connections, flanges, and valves may also be a cause of equipment leak emissions. 

The current NESHAP requires that the production facility monitor components using a 

leak detection and repair (LDAR) program as described in 40 CFR part 61, subpart V. For most 

components, this requires monthly inspection of the components using a volatile organic 

compound (VOC) detection instrument. If a leak greater than 10,000 parts per million is 

detected, then the facility is required to repair that leak in 15 days.

1.2.2 Natural Gas Transmission and Storage MACT

The natural gas transmission and storage source category includes the pipeline transport, 

storage, and processing of natural gas prior to entering the final pipeline of the local distribution 

company that delivers natural gas to the final end user.

Dehydration Units

As described above, dehydration units remove water and other condensates from the 

natural gas stream prior to going to the distribution company. The subpart HHH requirements 

are applicable to dehydration units that process an actual annual average flow rate of greater than 

or equal to 10 MMscf/d and emit greater than or equal to 1 tpy.

The current NESHAP requires that the emissions from a dehydration unit be controlled 

using a control device or series of control devices that reduce the HAP mass emissions by 95 

percent, or reduce the benzene emissions to less than 1 tpy.
4

2.0 PRACTICES, PROCESSES, AND CONTROL TECHNOLOGIES

For the purpose of reviewing the MACT standards, EPA considered a “development” in

practices, processes, and control technologies to be: 

 Any add-on control technology or other equipment (e.g., floating roofs for storage 

vessels) that was not identified and considered during MACT development, 

 Any improvements in add-on control technology or other equipment (that was identified 

and considered during MACT development) that could result in significant additional 

emission reduction,

 Any work practice or operational procedure that was not identified and considered during 

MACT development, and

 Any process change or pollution prevention alternative that could be broadly applied that 

was not identified and considered during MACT development.

Table 1 summarizes the practices, processes, and control technologies considered during 

the development of the MACT standards for these categories. This is followed by descriptions 

of the searches for developments since that time. The specific information sources that were 

consulted in this effort included EPA’s RACT/BACT/LAER clearinghouse (section 2.1), and 

direct correspondence with the industry (section 2.2).

2.1 RACT/BACT/LAER Clearinghouse

Under EPA's New Source Review (NSR) program, if a company is planning to build a 

new plant or modify an existing plant such that air pollution emissions will increase by a 

specified threshold, then the company must obtain an NSR permit. The NSR permit is a 

construction permit which requires the company to minimize air pollution emissions by either

changing the process to prevent air pollution and/or installing air pollution control equipment. 

In obtaining an NSR permit, a source will be required to install one of the following:

 Reasonably Available Control Technology (RACT), is required on existing 

sources in areas that are not meeting national ambient air quality standards (i.e., 

non-attainment areas). RACT is a control technology that is reasonably available, 

and both technologically and economically feasible. 

 Best Available Control Technology (BACT), is required on major new or 

modified sources in attainment areas and is an emissions limitation that represents 

the maximum degree of control that a source can achieve. BACT can be add-on 

control equipment or process modification.

 Lowest Achievable Emission Rate (LAER), is required on major new or modified 

sources in non-attainment areas and represents the most stringent emission 

limitation contained in any State implementation plant (SIP) or the most stringent 

emission limitation achieved in practice by a source.

BACT and LAER (and sometimes RACT) are determined on a case-by-case basis, 

usually by State or local permitting agencies. EPA established the RACT/BACT/LAER 

Clearinghouse, or RBLC, to provide a central data base of air pollution technology information 

(including past BACT and LAER decisions contained in NSR permits) to promote the sharing of 

information among permitting agencies and to aid in future case-by-case determinations. 
5

Table 1. Summary of Practices, Processes, and Control Technologies Identified and 

Considered During the Oil and Natural Gas Production and Gas Transmission and Storage 

MACT Development

Source 

Category/

Emission 

Source

Practices, Processes, and Control Technologies Considered 

During MACT Development

Determined to be 

Feasible Under 

MACT 

Standards?

Oil and Natural Gas Production

Glycol 

Dehydrators

Add-on controls (condensers, catalytic incinerators, thermal 

incinerators, carbon bed absorbers) Yes

Pollution prevention Yes

A combination of add-on controls and pollution prevention Yes

Storage Vessels

with the 

Potential for 

Flash Emissions

Floating roofs with specified seals and fittings No1

Add-on controls (condensers, catalytic incinerators, thermal 

incinerators, carbon bed absorbers) Yes

Pollution prevention Yes

Equipment 

Leaks

Leak detection and repair programs Yes

Specific equipment modifications Yes

Gas Transmission and Storage

Glycol 

Dehydrators

Add-on controls (condensers, catalytic incinerators, thermal 

incinerators, carbon bed absorbers) Yes

Pollution prevention Yes

A combination of add-on controls and pollution prevention Yes

 

1 U.S. Environmental Protection Agency, Office of Air Quality Planning and Standards. Research Triangle Park, 

NC. National Emission Standards for Hazardous Air Pollutants for Source Categories: Oil and Natural Gas 

Production and Natural Gas Transmission and Storage. Background Information Document for Proposed Standards. 

EPA-453/R-94-079a.
6

However, data in the RBLC are not limited to sources subject to RACT, BACT, and LAER 

requirements. Noteworthy prevention and control technology decisions and information are 

included even if they are not related to past RACT, BACT, or LAER decisions.2

The RBLC provides several options for searching the permit database on-line to locate 

applicable control technologies. A basic search of the RBLC was conducted by specifying the 

process category, pollutant, permit dates, and State. The search specified VOC- and HAPemitting processes in the Petroleum/Natural Gas Production categories with permits dating back 

to 1997. The search results included the following data fields: 

 Facility Name, and State

 Standard Industrial Classification (SIC), and North American Industry Classification 

System (NAICS) 

 Process Name and Description

 Control Technology and Emission Limit

 Percent Efficiency of Control

Table 2 presents processes, practices, and control technologies that were found in the 

RBLC for the Petroleum/Natural Gas Production categories. More detailed example results of 

the search are presented in Attachment 1.

As shown in Table 2, the practices, processes, and control technologies are all examples 

of the types of emission reduction techniques that were considered in the development of the Oil 

and Natural Gas Production and Gas Transmission and Storage MACT Development. Therefore, 

this exercise did not reveal any developments in practices, processes, or control technologies.

2.2 Current EPA LDAR Programs

The current subpart HH equipment leak standards require compliance with specific 

provisions of 40 CFR part 61, subpart V. This subpart V-level LDAR program requires monthly 

monitoring of valves and a leak definition of 10,000 ppm. Since the promulgation of the subpart 

HH standards, EPA has developed a more stringent LDAR program (40 CFR part 60, subpart 

VVa) that lowers the leak definition to 500 ppm and includes the annual monitoring of 

connectors. There have also been advancements in optical gas imaging and ultrasound LDAR 

monitoring. These instruments measure the magnitude of the leak, but are unable to measure the 

concentration of the leak. The general control device and work practice requirements in 40 CFR 

part 63, subpart A allow for the use of these instruments as an alternative to the Method 21 

monitoring. 

2.3 Natural Gas STAR

New practices, processes, and control technologies were also reviewed from the Natural 

Gas STAR program. The Natural Gas STAR Program is a flexible, voluntary partnership 

between EPA and industry throughout the oil and gas sector. This program encourages oil and 

natural gas companies to adopt cost-effective technologies and practices that improve operational 

 

2 Technology Transfer Network: Clean Air Technology Center. RACT/BACT/LAER Clearinghouse Basic 

Information. http://www.epa.gov/ttn/catc/rblc/htm/welcome_eg.html. 
7

efficiency and reduce pollutant emissions. The program provides the oil and natural gas industry 

with information on new techniques and developments to reduce pollutant emissions from the 

various processes.

Table 2. Summary of the RBLC Processes, Practices, and Control Technologies for Glycol 

Dehydrators, Storage Vessels with the Potential for Flash Emissions, and Equipment Leaks

Control Method

Identified in RBLC

Considered under 

MACT? (Y/N) Comments

Glycol Dehydrators

Thermal Oxidizer Y

Catalytic Oxidizer Y

Condenser Y

Enclosed Flare Y While this technology was considered under 

MACT, it does not achieve the current MACT 

emission reduction.

Pollution Prevention Y

Storage Vessels with the Potential for Flash Emissions

Thermal Oxidizer Y

Catalytic Oxidizer Y

Condenser Y

Enclosed Flare Y This technology does not achieve the current 

MACT emission reduction.

Pollution Prevention N These options are process modifications or 

operating limitations and were not considered 

under MACT.

Equipment Leaks

Leak Detection and 

Repair

Y

Low Emission Design 

Equipment

N This technology has not yet been proven to be 

effective for reducing emissions.

Glycol Dehydrators

The Natural Gas STAR program listed the following control techniques for glycol 

dehydrators:

 Optimize Glycol Circulation Rates3- By optimizing the glycol circulation rate, the 

facility can prevent the over circulation of the glycol solution in the dehydrator, thus 

reducing the potential emissions of HAP. Over circulation of the glycol solution does not 

significantly reduce the moisture content in the natural gas; however it does increase 

HAP emissions.

 

3 EPA (2006). Lessons Learned: Optimize Glycol Circulation and Install Flash Tank Separators in Glycol 

Dehydrators. Natural Gas STAR.
8

 Flash Tank Separator (FTS) Installation4- The installation of a flash tank separator can 

capture the methane that flashes from rich glycol in an energy-exchange pump. The 

captured emissions can be routed to a control device or re-circulated back to the natural 

gas feed line.

 Electric Pump Installation5- Gas-assisted pumps are used in remote areas that do not 

have an electrical power supply and are designed to take advantage of the energy of highpressure natural gas entrained in the rich (wet) glycol solution leaving the gas contactor. 

The seals in these pumps wear over time and result in contamination of the lean (dry) 

glycol solution making it less efficient in dehydrating the gas, which increases the glycol 

circulation rates, and increases HAP emissions.

 Re-route Glycol Skimmer Gas6- Rerouting the condensate separator gas, called skimmer 

gas, to the reboiler firebox or other low pressure fuel gas systems for fuel use can reduce 

VOC and HAP emissions. No information was provided on the level of VOC and HAP 

emission reductions.

 Replace Glycol Dehydrators with Methanol Injection7- Replacing a glycol gas 

dehydrator with methanol injection can be a more efficient and simpler method of 

controlling gas hydrate formation in gas lines than glycol dehydration. Methanol 

injection prevents hydrate formation in the natural gas and eliminates HAP emissions 

from the glycol dehydrator. This technology has been used for low pressure systems, but 

there is no information on the effectiveness of this technology for high pressure systems. 

In addition, field personnel are required to be on-site to operate the technology.

 Replace Glycol Dehydrators with Desiccant Dehydrators8- Replacing glycol dehydrators 

with desiccant dehydrators reduces methane, VOC, and HAP emissions by 99 percent by 

passing the wet gas through a drying bed of desiccant tablets. The tablets pull moisture 

from the gas and gradually dissolve in the process. This technology is feasible for low 

temperature, high pressure processing facilities, but has not been proven for gas volumes 

great than 5 million cubic feet per day (5 MMscfd).

 Replace Glycol Dehydrator with Separators and In-line Heaters9- Pipeline gas is 

expanded and auto-refrigerated in a cyclone separator to enhance water condensation and 

separation. The gas is then reheated to restore the gas to a dew point well below any 

conditions in the distribution system. Since no glycol is used to remove water from gas, 

VOC and HAP emissions from a glycol dehydrator are avoided. This technology is only 

appropriate for cold weather climates.

The optimization of the glycol circulation rates and the flash tank separator options were 

used in the MACT technology analysis from the Natural Gas STAR options. The other options 

were considered to be new or emerging technologies and have not been proven to work for all 

glycol dehydrators in the production or transmission source categories.

 

4 EPA (2006). Lessons Learned: Optimize Glycol Circulation and Install Flash Tank Separators in Glycol 

Dehydrators. Natural Gas STAR.

5 EPA (2006). Lessons Learned: Replacing Gas-Assisted Glycol Pumps with Electric Pumps. Natural Gas STAR.

6

EPA (2004). Partner Reported Opportunities: Reroute Glycol Skimmer Gas. Natural Gas STAR.

7 EPA (2004). Partner Reported Opportunities: Replace Glycol Dehydrators with Methanol Injection. Natural Gas 

STAR.

8 EPA (2006). Lessons Learned: Replacing Glycol Dehydrators with Desiccant Dehydrators. Natural Gas STAR.

9 EPA (2004). Partner Reported Opportunities: Replace Glycol Dehydrator With Separators and In-line Heaters. 

Natural Gas STAR.
9

Storage Vessels

The Natural Gas STAR program listed the following control techniques for storage 

vessels:

 Pressurized Condensate Tanks10– Pressurizing the condensate tanks allows the methane 

or other organic compounds to remain saturated in the condensate. The condensate can 

then be transported using trucks to a gas plant for economic recovery of gas liquids and 

associated methane, VOC, and HAP. This option requires pressurized transport vehicles, 

which are not allowed under MACT.

 Vapor Recovery Units11– Can be used to capture 95 percent of the vapor emissions from 

storage tanks and convert to methane and hydrocarbon liquids using separators or suction 

scrubber. 

Both of the above technologies were considered under the original MACT and do not 

represent developments in practices, processes, or control technologies.

Equipment Leaks

 Ultrasound Leak Detection12- Ultrasound leak detectors are used to reveal high 

frequency sounds associated with gas leakage. The ultrasound detector indicates whether 

the valve is tightly shut and the magnitude of leakage.

 Directed Inspection and Maintenance13- A directed inspection and maintenance program 

begins with a baseline survey to identify and quantify leaks. Repairs are then made to 

only the leaking components that are cost-effective to fix, based on criteria such as repair 

cost, expected life of the repair, and payback period. Subsequent surveys are designed 

based on data from previous surveys, allowing operators to concentrate on the 

components that are most likely to leak and are profitable to repair.

 Compressor Rod Packing Systems14– Increased frequency of reciprocating engine 

compressor rod packing replacement can reduce methane, VOC, and HAP emissions

from compressors.

 Replacement of Wet Seals with Dry Seals15– Replacement of wet seals with dry seals 

reduces operating costs and methane, VOC, and HAP emissions from centrifugal 

compressors.

These control options were not considered to be appropriate for MACT. The directed 

inspection and maintenance program was not considered because it is based on the criteria of 

cost of repair versus emission reductions. The ultrasonic leak detection provides the magnitude 

of the leak, but does not quantify the leak. Therefore, this option was not was not considered for 

 

10 EPA (2004). Partner Reported Opportunities: Install Pressurized Storage of Condensate. Natural Gas STAR.

11 EPA (2006). Lessons Learned: Installing Vapor Recovery Units on Crude Oil Storage Tanks. Natural Gas STAR.

12 EPA (2004). Partner Reported Opportunities: Use Ultrasound to Identify Leaks. Natural Gas STAR.

13 EPA (2006). Lessons Learned: Directed Inspection and Maintenance at Gas Processing Plants and Booster

Stations. Natural Gas STAR. 

14 EPA (2006). Lessons Learned: Reducing Methane Emissions from Compressor Rod Packing Systems. Natural 

Gas STAR.

15 EPA (2006). Lessons Learned: Replacing Wet Seals with Dry Seals in Centrifugal Compressors. Natural Gas

STAR.
10

MACT technology review. The compressor rod packing and dry seal replacement options 

reduce leaking emissions from compressors. These options were not considered as options for 

equipment leaks because of the low HAP content of the leaking gas. However these compressor 

options will be reviewed for the NSPS for each of the oil and gas segments.

3.0 CONCLUSIONS

In order to identify developments in practices, processes, or control technologies that 

could be used to further reduce emissions from Oil and Natural Gas Production and Natural Gas 

Transmission and Storage, the following sources of information were searched: EPA’s 

RACT/BACT/LAER clearinghouse, and Natural Gas STAR.

For glycol dehydrators, many of the practices, processes, or control technologies listed by 

the Natural Gas STAR program were not identified and evaluated during the original MACT 

development. However, most of these practices are considered to be new and unproven practices 

that may are not applicable to all production or transmission facilities. Only one of the 

technologies identified in the Natural Gas STAR literature, glycol dehydrator with a desiccant 

dehydrator, would result in zero HAP emissions. However, this technology cannot be used for 

natural gas operations that operate at high temperature, high volume, or low pressure. Therefore, 

this technology was not considered as MACT for the natural gas and oil production or natural 

gas transmission and storage source categories. The RBLC results did not identify any practices, 

processes, and control technologies applicable to the emission sources in these categories that 

were not identified and evaluated during the original MACT development. 

The applicable technologies for storage vessels with the potential for flash emissions 

identified in the Natural Gas STAR program are comparable to the cover and control 

technologies currently required under the existing MACT. Therefore, these Natural Gas STAR 

technologies would not result in any additional HAP reductions than what is achieved under the 

current MACT. The RBLC results did not provide any new technologies or practices that were 

not identified in the original MACT.

For equipment leaks, the RBLC and Natural Gas STAR programs did not provide any 

additional practices or technologies for reducing HAP from equipment leaks. The only new 

developments for equipment leaks were found in EPA’s current LDAR programs. Both the 40 

CFR part 60, subpart VVa and the alternative work practices under 40 CFR part 60, subpart A

provide more stringent requirements than the subpart V standards. The subpart VVa-level 

program has a leak definition of 500 ppm and includes the annual monitoring of connectors. The 

general control device and work practice requirements in 40 CFR part 60, subpart A allow for 

the monthly monitoring of components using an optical gas imaging or ultrasound equipment 

with an annual Method 21–based LDAR check. Because the current leak definition under 

subpart HH is the same as the leak definition in subpart VV, which was evaluated in the 

Technical Support Document16 (TSD) for the NSPS, the same equipment leak options could also 

be evaluated for the NESHAP. The ratio of VOC to HAP in the production natural gas stream is 

approximately 20 to 1; therefore the HAP reduction can be expected to be 1/20th of the VOC 

reduction calculated in the TSD.

 

16 U.S. EPA, Background Technical Support Document for Proposed Standards - New Source Performance 

Standards for the Oil and Natural Gas Industry, July 2011.
11

In the TSD, the estimated incremental cost for moving from a subpart VV LDAR 

program to a subpart VVa LDAR program was determined to be $3,340 per ton of VOC. Using 

the 20-to-1 VOC to HAP ratio, the incremental cost to control HAP at the subpart VVa level 

would be approximately $66,800 per ton of HAP. Other LDAR options considered in TSD 

included the monthly monitoring using an optical gas imaging camera with an annual EPA

Method 21 check. The HAP cost effectiveness of this option was approximately $129,000 per 

ton of HAP, if purchasing the camera; and $93,000 per ton of HAP, if renting the camera. 

Emission reductions from monthly optical gas imagining with no Method 21 check, and annual 

optical gas imaging with no Method 21 check could not be quantified and, therefore, no cost 

effectiveness values were determined. Based on these estimates, it was determined that the 

additional costs of these options were not justified.

In addition to the plant-wide LDAR program evaluations, a component cost analysis was 

also evaluated at gas processing plants for the 40 CFR part 60, subpart VVa-level of control. 

The component analysis was not performed for optical gas imaging, because this technology is 

not amenable to a component to component analysis. The component analysis for the subpart 

VVa-level of control for connectors has an incremental cost effectiveness of $4,360 per ton for 

VOC for connectors and $144 per ton for VOC for valves. This converts to $87,200 per ton for 

connectors and $2,880 per ton for valves using the 20 to 1 VOC to HAP ratio. The additional 

cost for the more stringent requirement for connectors was determined not to be justified, but the 

additional cost for valves is justified. Therefore, the leak definition for valves in 40 CFR part 63, 

subpart HH is proposed to be lowered to an instrument reading of at least 500 ppm as a result of

the technology review.
ATTACHMENT 1

INFORMATION FROM THE RACT/BACT/LAER CLEARINGHOUSE
RBLC Information for Glycol Dehydrators

RBLCID FACILITY_NAME SIC_CODE NAICS_CODE PROCESS_NAME PROCCESS_TYPE PRIMARY_FUEL THROUGHPUT THROUGHPUT_UNIT PROCESS_NOTES" POLLUTANT CONTROL_METHOD_CODE CONTROL_METHOD_DESCRIPTION EMISSION_LIMIT_1 EMISSION_LIMIT_1_UNIT PERCENT_EFFICIENCY

MI-0305

CONSUMERS ENERGY (MUSKEGON 

RIVER COMPRESSOR) 4925 486210 GLYCOL DEHYDRATOR, TRIETHYLENE 50.999 NATURAL GAS 260 MMSCF/DAY

VOC DESTRUCTION EFFICIENCY MUST 

BE TESTED TO ASSURE 98%. THE 

APPLICABLE MACT IS 40 CFR 63.1274 

(D) (2). GLYCOL RATE 15-30 GPM. Benzene A

THERMAL OXIDIZER. DESIGNED FOR 1400 

DEGREES F AND 0.5 SECOND RESIDENCE. THE 

THERMAL OXIDIZER IS NEW. 0.8 T/YR 9 8

MI-0323

KCS MICHIGAN RESOURCES (MAYFIELD 

28) 1311 211111 GLYCOL DEHYDRATOR 50.009 NATURAL GAS 2.4 MMSCF/D

GLYCOL RECIRCULATION RATE MAXIMUM 0.28 GPM. Benzene A CONDENSER 0.27 T/YR 0

MI-0323

KCS MICHIGAN RESOURCES (MAYFIELD 

28) 1311 211111 GLYCOL DEHYDRATOR 50.009 NATURAL GAS 2.4 MMSCF/D

GLYCOL RECIRCULATION RATE MAXIMUM 0.28 GPM. VOC A

FLASH TANK ADDED. DOWNCOMER 

CONDENSER EXHAUST TEMPERATURE MAINTAINED AT 100 DEGREES F OR LESS. 3.7 T/YR 0 MI-0324 SAVOY ENERGY (TOWER) 1311 211111 GLYCOL DEHYDRATOR 50.999 NATURAL GAS 300000 CF/D REBOILER STILL STACK Benzene N N/A 0.22 T/YR 0

MI-0324 SAVOY ENERGY (TOWER) 1311 211111 GLYCOL DEHYDRATOR 50.999 NATURAL GAS 300000 CF/D REBOILER STILL STACK VOC P

PRODUCTION IS LIMITED TO 300000 CF/DAY, 

12-MONTH ROLLING TIME PERIOD 13.5 T/YR 0

MI-0325

MICHIGAN CONSOLIDATED GAS (BELLE 

RIVER MILLS) 4923 211111 GLYCOL DEHYDRATOR 50.999 NATURAL GAS 986 MMSCF/D

CONSISTS OF TWO TOWERS, TWO 15 

GPM CIRCULATION PUMPS Benzene A ENCLOSED FLARE CONTROL OF STILL OFF GAS. 0.43 T/YR 9 9

MI-0325

MICHIGAN CONSOLIDATED GAS (BELLE 

RIVER MILLS) 4923 211111 GLYCOL DEHYDRATOR 50.999 NATURAL GAS 986 MMSCF/D

CONSISTS OF TWO TOWERS, TWO 15 

GPM CIRCULATION PUMPS VOC A

ENCLOSED FLARE CONTROL OF STILL OFF-GAS. 

EXCEEDS REQUIREMENT OF MACT, 40 CFR 

63.1274 (D)(2) 9 T/YR 9 9 MI-0330 SAVOY ENERGY (OTSEGO LAKE) 1311 211111 GLYCOL DEHYDRATOR 50.999 NATURAL GAS 350000 CF/D REBOILER STILL STACK Benzene N NA 0.49 T/YR 0

MI-0330 SAVOY ENERGY (OTSEGO LAKE) 1311 211111 GLYCOL DEHYDRATOR 50.999 NATURAL GAS 350000 CF/D REBOILER STILL STACK VOC P

PRODUCTION IS LIMITED TO 350000 CF/DAY, 

12-MONTH ROLLING TIME PERIOD. HAPS ARE 

ALSO LIMITED TO MINOR SOURCE STATUS. 

DOWNCOMER CONDENSER TEMPERATURE MUST BE 105 DEGREES F OR LESS. 12.6 T/YR 0 MI-0332 SAVOY ENERGY (FREDERIC TWP) 1311 211111 GLYCOL DEHYDRATOR 50.999 600000 CF/D 100000 BTU REBOILER Benzene N NA 0.22 T/YR 0

MI-0332 SAVOY ENERGY (FREDERIC TWP) 1311 211111 GLYCOL DEHYDRATOR 50.999 600000 CF/D 100000 BTU REBOILER VOC P

PRODUCTION IS LIMITED TO 600000 CF/DAY; 

12-MONTH ROLLING AVERAGE. HAPS ARE 

ALSO LIMITED TO MINOR SOURCE STATUS. 

ABOUT ONE-HALF VOC FROM STILL, ONE-HALF 

FROM GAS-DRIVEN GLYCOL PUMP. 13.9 T/YR 0 MI-0341 ANR PIPELINE COMPANY - REED CITY 4923 486210 GLYCOL REGENERATION, REBOILER STILL VENT 50.002 120 SCFM regeneration of glycol solution. Benzene A THERMAL OXIDIZER, CONDENSER BACKUP. 1 T/YR 9 5 MI-0341 ANR PIPELINE COMPANY - REED CITY 4923 486210 GLYCOL REGENERATION, REBOILER STILL VENT 50.002 120 SCFM regeneration of glycol solution. VOC A THERMAL OXIDIZER, CONDENSER BACKUP. 9 0 LB/D 9 5

TX-0364 SALT CREEK GAS PLANT 1321 211112 GLYCOL STILL VENT, EPN14 50.005 Benzene N NONE INDICATED 0.34 LB/H 0

TX-0364 SALT CREEK GAS PLANT 1321 211112 GLYCOL REBOILER, EPN11 13.31 NAT GAS 2.5 MMBTU/H VOC N NONE INDICATED 0.02 LB/H 0

TX-0364 SALT CREEK GAS PLANT 1321 211112 GLYCOL STILL VENT, EPN14 50.005 VOC N NONE INDICATED 9.42 LB/H 0

TX-0465 SALT CREEK GAS PLANT 1321 221210 GLYCOL VENT 64.003 Benzene N 0.34 LB/H 0

TX-0465 SALT CREEK GAS PLANT 1321 221210 GLYCOL REBOILER 19.6 2.5 MMBUT/H VOC N 0.02 LB/H 0

TX-0465 SALT CREEK GAS PLANT 1321 221210 GLYCOL VENT 64.003 VOC N 9.42 LB/H 0
RBLC Information for Storage Vessels

RBLCID FACILITY_NAME SIC_CODE NAICS_CODE PROCESS_NAME PROCCESS_TYPE THROUGHPUT THROUGHPUT_UNIT PROCESS_NOTES" POLLUTANT CONTROL_METHOD_CODE CONTROL_METHOD_DESCRIPTION EMISSION_LIMIT_1 EMISSION_LIMIT_1_UNIT PERCENT_EFFICIENCY

AK-0047 MILNE POINT PRODUCTION FACILITY 1311 211111 TANK, T-6101A 42.005 147000 GAL VOC P

COMPLIANCE WITH THE RECORDKEEPING 

PROVISIONS OF 40 CFR SUBPART KB. 0 0

AK-0047 MILNE POINT PRODUCTION FACILITY 1311 211111 TANK, T-2002 64.004 11800 GAL VOC P

COMPLIANCE WITH THE RECORDKEEPING 

PROVISIONS OF 40 CFR SUBPART KB. 0 0

AK-0047 MILNE POINT PRODUCTION FACILITY 1311 211111 VENTS 50.002

UNITS CATEGORIZED AS VENTS AND 

INCLUDED IN THIS ENTRY INCLUDE: OIL 

RESERVE TANKS; VENT HEADER 

(FLOTATION CELLS, COMPRESSOR 

VENTS, TEG REBOILER, DRAIN PURGE, 

VENT PURGE GAS, BACKWASH 

CLARIFIER, PRODUCED WATER SURGE 

TANK, TANK T-5853, AND SAND SLURRY 

TANK); OTHER TANKS (T-2001, T-6102A, 

T-6102B). VOC P

GAS BLANKETING AND BACK PRESSURE RELIEF 

VALVE FOR OIL RESERVE TANKS. WITHIN 60 D 

OF ISSUANCE, DO NOT VENT GAS TO 

ATMOSPHERE FROM PRODUCED WATER 

SURGE TANK. ISOLATE PRESSURE CONTROL 

VALVE. 0 0

LA-0212 ZACHARY STATION 4613 486910

11.75 MM GAL GASOLINE/DISTILLATES TANKS 

(T-1 & T-14) 42.006 423 MM GALS/YR VOC P INTERNAL FLOATING ROOFS 3.16 LB/H 0

LA-0212 ZACHARY STATION 4613 486910

6.61 MM GAL GASOLINE/DISTILLATES TANK (T4 ) 42.006 238 MM GALS/YR VOC P INTERNAL FLOATING ROOF 2.17 LB/H 0

LA-0212 ZACHARY STATION 4613 486910

6.61 MM GAL GASOLINE/DISTILLATES TANK (T9 ) 42.006 238 MM GALS/YR VOC P INTERNAL FLOATING ROOF 2.11 LB/H 0

LA-0212 ZACHARY STATION 4613 486910 394,813 GAL TRANSMIX TANK (T-13) 42.006 14.21 MM GALS/YR VOC P INTERNAL FLOATING ROOF 0.66 LB/H 0

LA-0228 BATON ROUGE JUNCTION FACILITY 4613 486910

EQT026-EQT030 FIVE GASOLINE TANKS (T001-

T005) 42.006 240000 BBL (EACH) VOC P

INTERNAL FLOATING ROOFS AND SUBMERGED 

FILL PIPES 59.7 T/YR 0

LA-0228 BATON ROUGE JUNCTION FACILITY 4613 486910

EQT031-EQT035 FIVE DISTILLATE TANKS (T006-

T010) 42.005 240000 BBL (EACH) VOC P

SUBMERGED FILL PIPES AND 

PRESSURE/VACUUM VENTS 4 5 T/YR 0

LA-0228 BATON ROUGE JUNCTION FACILITY 4613 486910 FUG003 TANK CLEANING (TC01) 42.004 VOC P

LIMIT TANK CLEANING TO 2 TIMES PER ANY 12 

CONSECUTIVE MONTH PERIOD. MINIMIZE THE 

TIME BEFORE REMOVING LIQUID HEELS AND 

SLUDGE FROM THE TANK BOTTOM 16.07 T/YR 0

LA-0232 STERLINGTON COMPRESSOR STATION 4922 486210 CONDENSATE STORAGE TANK 42.005 5760 BBL/YR 100 BBL VOLUME VOC P SUBMERGED FILL PIPE 1.28 LB/H 0
RBLC Information for Equipment Leaks

RBLCID FACILITY_NAME SIC_CODE NAICS_CODE PROCESS_NAME PROCCESS_TYPE PROCESS_NOTES POLLUTANT CONTROL_METHOD_CODE CONTROL_METHOD_DESCRIPTION EMISSION_LIMIT_1 EMISSION_LIMIT_1_UNIT PERCENT_EFFICIENCY

CA-1145

BREITBURN ENERGY - NEWLOVE LEASE, 

ORCUTT HILL FIELD 1311 212299 OIL AND GAS: FUGITIVE COMPONENTS 13.39

EQUIP: LOW-EMISSION DESIGN VALVES, 

CONNECTIONS AND SEALS (SEE BELOW), MFR: 

VARIOUS, TYPE: VALVES, FLANGES, PUMP SEALS, 

COMPRESSOR SEALS, ETC, MODEL: VARIOUS, FUNC 

EQUIP: PIPING COMPONENTS IN OILFIELD 

OPERATIONS, FUEL_TYPE: , SCHEDULE: CONTINUOUS, 

H/D: 24, D/W: 7, W/Y: 365, NOTES: VALVES: 

BELLOWS, DIAPHRAGM SEAL, SPRING-LOADED 

PACKING, EXPANDABLE PACKING, GRAPHITE 

PACKING, PTE-COATED PACKING, PRECISION 

MACHINED STEM, SEALANT INJECTION AND LDAR: 

100 PPMV THC. FLANGES/CONNECTORS/OTHER: 

WELDED, NEW GASKET RATED TO 150% OF PROCESS 

PRESSURE AT PROCESS TEMPERATURE. LDAR: 100 

PPMV THC COMPRESSOR SEALS (ROTARY DRIVE): 

VENTED TO VAPOR RECOVERY OR CLOSED VENT, 

DUAL/TANDEM MECHANICAL SEALS, LEAKLESS 

DESIGN (E.G. MAGNETIC DRIVE). LDAR: 100 PPMV 

THC COMPRESSOR SEALS (RECIPROCATING DRIVE): 

VENTED TO VAPOR RECOVERY, ELASTOMER 

BELLOWS, O-RING SEALS, DRY RUNNING SECONDARY 

CONTAINMENT SEALS. LDAR: 100 PPMV THC PUMP 

SEALS: VENTED TO VAPOR RECOVERY OR CLOSED 

VENT, DUAL/TANDEM MECHANICAL SEALS. LDAR: 

500 PPMV THC PRDS: VENTED TO VAPOR RECOVERY 

OR CLOSED VENT, SOFT-SEAT DESIGN. LDAR: 100 

PPMV THC SOURCE TEST RESULTS: VOC A

LOW EMISSIONS DESIGN AND LOWER LDAR 

THRESHOLD (SEE BELOW) 100 PPMV 0

IL-0073 EXXONMOBIL OIL CORPORATION 2911 324110 FUGITIVES 50.007 VOC N 3.76 T/YR 0

LA-0228 BATON ROUGE JUNCTION FACILITY 4613 486910 FUG002 FUGITIVE EMISSIONS 42.004 VOC P

CONDUCT A LEAK DETECTION AND REPAIR 

PROGRAM AS SPECIFIED BY 40 CFR 63 

SUBPART R 7.44 T/YR 0

TX-0364 SALT CREEK GAS PLANT 1321 211112 FUGITIVES, NGLFUG 50.007 VOC N NONE INDICATED 9.08 LB/H 0

TX-0364 SALT CREEK GAS PLANT 1321 211112 FUGITIVES, CO2FUG 50.007 VOC N NONE INDICATED 9.33 LB/H 0

TX-0440 CORPUS CHRISTI LNG 4922 221210 FUGITIVES (4) 50.007 VOC N 1.96 LB/H 0

TX-0454

EL PASO NATURAL GAS CORNUDAS 

COMPRESSOR STATION 4922 486210 FUGITIVES (4) 64.002 VOC N 0.13 LB/H 0

TX-0457

CITY PUBLIC SERVICE LEON CREEK 

PLANT 351 333311 PLANT FUGITIVES (4) 64.002 VOC N 0.07 LB/H 0

TX-0465 SALT CREEK GAS PLANT 1321 221210 FUGITIVES (4) 64.002 VOC N 9.08 LB/H 0

TX-0465 SALT CREEK GAS PLANT 1321 221210 FUGITIVES 64.002 VOC N 9.33 LB/H 0

TX-0492

VIRTEX PETROLEUM COMPANY 

DOERING RANCH GAS PLANT 2911 324110 FUGITIVES (4) 50.007

TOTAL UNCONTROLLED FUGITIVE EMISSIONS ARE 

LESS THAN 10 TPY, SO NO MONITORING IS 

REQUIRED. THE COMPANY WILL IMPLEMENT DAILY 

WALKTHROUGHS TO INSPECT THE PIPING. THERE 

ARE ALSO H2S MONITORS ON SITE TO CAPTURE ANY 

H2S LEAKS. VOC N 0.88 LB/H 0